The present application relates generally to data processing systems and more particularly to data processing systems that include redundant elements.
Data processing systems are often provided with xe2x80x9credundantxe2x80x9d elements such as bus lines or system components in order to better ensure continued operation of a data processing system should an element of the data processing system fail. A redundant element may be xe2x80x9cswitched inxe2x80x9d to replace the failed element such that the data processing system continues to function as normal.
xe2x80x9cSwitching events,xe2x80x9d wherein redundant elements are switched in to replace failed elements, typically produce voltage transients on the system interconnect of the data processing system. Such transients can damage system components or incorrectly alter the logical state of system components, and data processing systems that include redundant elements typically include a mechanism for reducing the effects of transients. Prior mechanisms have typically concentrated on minimizing the energy or voltage of the transients by using filters that attenuate the transients as they occur. Unfortunately, transients that have been attenuated can nonetheless alter the logical state of system components, which is undesirable.
Therefore, it is an object of the present invention to provide a mechanism that allows system components to ignore transients that occur during switching events.
This and other objects of the invention are provided by a method for protecting system components from transients that arise on a system interconnect during switching events. The system components operate in a normal mode of operation prior to detection of the impending occurrence of a switching event wherein a first redundant element replaces a failed element. Upon detecting the impending occurrence of a switching event, an indication that the switching event is to occur is conveyed to the system components. The system components respond by entering a standby mode of operation wherein system components isolate their circuitry from the system interconnect during the switching event. The system components returning to the normal mode of operation in response to a triggering event.